Add persistence.existingClaim (bokysan#57)

This commit enables the user to provide an existing volume claim instead of having the image create a new one automatically.

README.md

@@ -457,6 +457,7 @@ Chart configuration is as follows:
 | `config.opendkim` | `{}` | Key-value list of general OpenDKIM options, e.g. `RequireSafeKeys: "yes"` |
 | `persistence.enabled` | `true` | Persist Postfix's queu on disk |
 | `persistence.accessModes` | `[ 'ReadWriteOnce' ]` | Access mode |
+| `persistence.existingClaim` | `""` | Provide an existing `PersistentVolumeClaim`, the value is evaluated as a template. |
 | `persistence.size` | `1Gi` | Storage size |
 | `persistence.storageClass` | `""` | Storage class |
 

helm/mail/templates/statefulset.yaml

@@ -99,13 +99,21 @@ spec:
           resources: {{ toYaml .Values.resources | nindent 12 }}
       {{- if .Values.persistence.enabled }}
       {{ if .Values.extraVolumes }}volumes: {{- toYaml .Values.extraVolumes | nindent 8 }}{{ end }}
+      {{- if .Values.persistence.existingClaim }}
+      volumes:
+        - name: {{ $fullName }}
+          persistentVolumeClaim:
+            {{- with .Values.persistence.existingClaim }}
+            claimName: {{ tpl . $ }}
+            {{- end }}
       {{- else }}
       volumes:
         - name: {{ $fullName }}
           emptyDir: {}
         {{- if .Values.extraVolumes }}{{- toYaml .Values.extraVolumes | nindent 8 }}{{ end }}
       {{- end }}
-  {{- if .Values.persistence.enabled }}
+      {{- end }}
+  {{- if and .Values.persistence.enabled (not .Values.persistence.existingClaim) }}
   volumeClaimTemplates:
     - metadata:
         name: {{ $fullName }}

helm/mail/values.yaml

@@ -96,5 +96,6 @@ persistence:
   enabled: true
   accessModes:
     - ReadWriteOnce
+  existingClaim: ""
   size: 1Gi
   storageClass: ""